Synthesis of novel Ln_xSb_(2-x)Se_3 (Ln: Lu~(3+), Ho~(3+), Nd~(3+)) nanomaterials via co-reduction method and investigation of their physical properties

摘要

Rare earth ion (Lu~(3+), Ho~(3+), Nd~(3+))-doped Sb_2Se_3 nanomaterials are synthesized by a co-reduction method in hydrothermal condition. Powder XRD patterns indicate that the Ln_xSb_(2-x)Se_3 crystals (Ln=Lu~(3+), x=0.00-0.12; Ho~(3+), x=0.00-0.1 and Nd~(3+), x=0.00-0.09) are isostructural with Sb_2Se_3. SEM images show that doping of Ho3+ ions in the lattice of Sb_2Se_3 results in nanorods while that in Nd~(3+)and Lu~(3+)leads to nanoflowers and nanoparticles, respectively. High-resolution transmission electron microscopic (HRTEM) studies reveal that the Sb_2Se_3 and Sb_(1.90) Ho_(0.1)Se_3are oriented in the [10-1] growth direction. UV-vis spectra show that an increasing concentration of Ln~(3+)ions increases the intensity of some peaks in the absorption spectrum of Sb_2Se_3 related to electronic transitions of the Ln~(3+) ions in case of Ho~(3+) and Nd~(3+) doped nanomaterials. Emission spectra of doped materials, in addition to the characteristic red emission peaks of Sb_2Se_3, show other emission bands originating from f-f transitions of the Ho~(3+) ions. The electrical conductance of Ln-doped Sb_2Se_3 is higher than the undoped Sb_2Se_3, and increases with temperature.